1. Field of Invention
The present invention relates to a LED circuit. More particularly, the present invention relates to a LED circuit having fast compensation mechanism.
2. Description of Related Art
LEDs are estimated to be four times as efficient as conventional incandescent lights. They are also claimed to be more economically sound than compact fluorescent bulbs that contain harmful mercury and are supposed to last a lot longer than the conventional lighting. Thus, LEDs may become the mainstream of the lighting technology.
The switching circuit in the LED circuit is to perform charge and discharge on the LEDs. The PWM in the switching circuit requires a RC circuit with large RC constant to perform compensation. However, the conventional design of the RC circuit with large RC constant can provide large amount of charging current but result in low discharging activity. Thus the switching activity of the LED circuit losses the linearity due to the RC circuit.
Accordingly, what is needed is a LED circuit with a new design of the switching circuit to provide the compensation mechanism without losing of the linearity.